In a conventional manufacturing method of an air conditioner, moisture was controlled in the following method. A refrigerant (R22, HCFC: hydrochlorofluorocarbon) is poured into the main body of the outdoor unit. The outdoor unit is then checked for refrigerant leaks. In the final process, to inspect the product characteristics, a dummy indoor unit is connected to the outdoor unit, and the system is inspected. When no problems are found, the product is completed. As a moisture control method in the man turning process, a specific amount of refrigerant is sampled, and the water content in the refrigerant sample is measured. That is, as mineral oil having a low moisture adsorption has been used as a compressor oil, it was sufficient to control only the moisture rate contained in the refrigerant in the refrigeration cycle.
Recently, however, as the environmental regulations have become stricter due to the destruction of the ozone layer and global warming, there is an urgent need for development of air conditioner using chlorine-free HFC (hydrofluorocarbon). Since the HFC refrigerant does not contain chlorine, it does not exhibit the lubricating quality of the conventional HCFC. Hence, the oil to be contained in an enclosed container is particularly required to be an oil compatible with an HFC refrigerant. The oil contained in an enclosed container is stirred by the HFC refrigerant discharged from the compression mechanism into the enclosed container, and is further stirred by a rotor of a motor. At this time, since the oil and refrigerant are compatible, the oil sufficiently accompanies the refrigerant discharged into the enclosed container, and sufficiently permeates the small parts of the sliding members of the machine. Therefore, together with the supply of oil from the oil pump, the lubricating performance is enhanced. As such oil, synthetic oil such as ester oil or ether oil as disclosed, for example, in Japanese Laid-open Patent No. 6-235570 has come to be used.
However, both ester oil and ether oil have a high moisture adsorption, and when used in a compressor containing such an oil, it is necessary to manufacture the air conditioner (outdoor unit) under stricter moisture control than before.
In the light of the problems of the moisture control in manufacturing the air conditioner using an HFC refrigerant in the conventional manufacturing method, it is an object of the invention to present a manufacturing method capable of controlling moisture of product sufficiently in a simple method.